Swivel for hoisting machinery.



A. O. GRAHAM. SWIVEL FOR HOISTING MACHINERY.

APPLICATION FILED JUNE11,1912.

Patented Dec. 24, 1912.

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ALBERT C. GRAHAM, 0F OILFIELDS, CALIFORNIA.

SWIVEL FOR HOISTING MACHINERY.

Specification of Letters Patent.

Patented Dec. 24, 1912.

Application filed June 11, 1912. Serial No. 703,028.

To all whom it may concern:

Be it known that I, ALBERT C. GRAHAM, a citizen of the United States, and a resident of Oilfields, in the county of Fresno and State of California, have invented a new and Improved Swivel for Hoisting Machinery, of which the following is a full, clear, and exact description.

Among the principal objects which the present invention has in view are: to provide a pivotal engagement for uniting the hoisting cable and the elevator links of a well casing; and to provide engagement means for uniting the parts of a hoisting mechanism constructed and arranged to minimize the weight and economize the cost of construction.

One embodiment of the present invention is disclosed in the structure illustrated in the drawing, in which the figure is a vertical side view of a swivel constructed and arranged in accordance with this invention and shown in conjunction with fragments of the elevator links of a hoisting mechanism for an oil well casing, a portion of the bail of the swivel block being in section to show the construction of the same.

The present device is designed particularly to replace the grab hooks now em ployed for lifting the casing of an oil well. Because of the excessive weights, running to fifty tons and more, of the casing the hooks are exceedingly bulky and heavy. Also the hooks are uncertain in their operation and are found to be liable to release from engagement at critical moments, causing the casing to drop in the well thereby damaging the structure materially. The necessary bulk of the hooks has heretofore increased the lifting weight required to be exerted upon the cables and has been for this reason objectionable. I overcome the several objections above noted by the employment of the swivel herein shown and described.

A block 5 of sufiicient strength is centrally perforated to receive rotatably therein abolt extension 6 integrally formed with and projected above a rectangular block 7. The upper portion of the bolt extenslon 6 is provided with a screw thread 8 which registers with threads formed in the heavy nut 9. The nut 9 is held in locked position on the bolt extension 6 by a pin 10 which is driven through registering perforations formed in the said extension 6 and nut 9.

The nut 9 is preferably seated upon a washer 11 interposed between the said nut and the upper face of the block 5. The block 5 is preferably rectangular in shape and is provided on opposite sides with gudgeons 12. The gudgeons 12 are passed through alined perforations formed in the lower ends of the loop bail 13. The gudgeons 12 form pivots on which the block 5 rocks to accommodate the exigencies of the load and the distribution thereof on the hoisting tackle. It will be understood that all the parts receiving the strain are properly constructed, due strength being given to each of the said parts.

The bolt extension 6 provides a vertically disposed pivot on which the load swung from the block 7 may rotate. The load swung from the block 7 is immediately carried by the pin 14 which is passed through alined perforations in the plate extensions 15 formed in the under side of the block 7 by cutting grooves 01' passages 16. The passages 16 are of a dimension sufficient to receive the elevator links 17, which links are secured mediately or immediately to the elevator casing.

In the operation of the device when constructed as shown and described the hoisting cable is attached to the bail 18. The pin 1 1 is withdrawn from across the passage 16 and the elevator links 17 are then introduced therein. The pin 14 is then re-threaded through the perforations in the extensions 15 and locked in operative position by means of a cotterpin 18. The pin 18 is secured by means of a small dropped chain 19 and an eyelet 20 to the block 7. After the pin 14 has been thus threaded and secured by the pin 18 it is adjusted until a perforation formed in the head 21 registers with a perforation formed in the adjacent extension 15 through which may be extended a holdin pin 22. The holding pin 22 is scctu'e against loss or displacement by a small chain 23 secured to the block 7 by means of an eyelet 24, as seen in the drawing.

It will be noted that due to the design and arrangement all strain imparted to the oints are what may be termed shear strains, or strains which in order to disarrange the relation of the parts require the shearing of the parts. All of the lifting members are arranged so that the strain is imposed upon the said members lineally, the full tensile strength of the various materials being thereby obtained. This permits the employment of lighter material than formerly employed in the construction of what has been above called hooks, and by reason of the swiveling of the joints on the vertical pivot extension 6 and the horizontal pivots or gudgeons 12 all balance or trim of the load is insured.

While I have herein shown the bearing between the block 5 and the washer 11 as being a smooth bearing it will be understood that I may substitute for the said smooth bearing any suitable roller bearing without passing beyond the scope of the present invention. This construction has not been shown in the drawing. Also it will be understood that while I have shown a block 7 having provision made for the engagement of two links 17, this may be altered without changing the scope of the invention by forming a single passage such as the passage 16 to receive a single link 17 when the hoisting mechanism calls for such an alteration.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. A swivel for hoisting machinery, comprising a bail; a pivot block mounted in bearings formed therein, said block having a central perforation; a hanger block having a screw-threaded bolt extension passing through said. perforation in said pivot block, said hanger block being provided with a plurality of parallel downwardly-opening passages formed by parallel extensions of said block said extensions being transversely perforated; and a pin to rest in the perforation of all of said extensions, to support the weight carried by said swivel.

2. A swivel for hoisting machinery, com prising a bail; a pivot block mounted in bearings formed in said bail, said block having a central perforation; a hanger block having a screw-threaded bolt extending through said perforation in the pivot block, said hanger block being provided with a plurality of parallel downwardly-opening passages formed by extensions of said. block, said extensions being transversely perforated and flared at the bottom to provide room for the connecting links of a supporting chain to swing therein; and a pin, to rest in said perforations to support the weight carried by said swivel.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALBERT C. GRAHAM. Witnesses IV. J. KILBY, HELEN KILBY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

